Although the underlying causes of glaucoma are not understood at this time, glaucoma is characterized by damage to the optic nerve, accompanied by a decrease in the normal visual field. One early warning sign of possible glaucomatous visual field loss is elevated IOP.
There are angiostatic agents which are known to lower IOP, see, for example, U.S. Pat. Nos. 4,876,250 and 5,371,078. These compounds are very effective in controlling ocular hypertension, but they usually exhibit a slow onset of action; that is, it can take several weeks before an IOP lowering effect is seen.
Other known IOP controlling agents, such as miotics, sympathomemetics, beta-blockers, carbonic anhydrase inhibitors, and prostaglandins are immediately effective in lowering IOP.
The compositions of the present invention contain an angiostatic agent which provides effective, long duration control of IOP and a second IOP lowering compound to provide immediate control of a patient's elevated IOP. This combination is more effective in that a patient's IOP can be lowered and controlled with less IOP spiking. In addition, the effectiveness of the combination is at least additive because the angiostatic agents lower IOP via a different mechanism than any of the second IOP lowering compounds described in this invention.